Sonochemical Synthesis of Ce-doped TiO2 Nanostructure: A Visible-Light-Driven Photocatalyst for Degradation of Toluene and O-Xylene

Abstract

Ce-doped TiO2 nanostructures (CeT) with different amounts of Ce (0.5, 0.75, 1.0, 1.5, and 2.0 wt.%) were synthesized using a sonochemical processing method. The physicochemical properties of the prepared samples were explored using UV-visible diffuse reflectance spectroscopy (UV-vis DRS), field-emission TEM (FE-TEM), XRD, X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), and surface area and pore size analyzers. The photocatalytic performance of the prepared CeT was assessed by monitoring their degradation efficiencies for gaseous toluene and o-xylene—widely known as significant indoor air pollutants—under daylight irradiation. The prepared CeT exhibited significantly improved photocatalytic performance towards the degradation of toluene and o-xylene, which was much higher than that observed for pure TiO2 and commercial P25 TiO2. Particularly, photocatalytic degradation efficiencies by the prepared CeT catalysts increased remarkably in the case of o-xylene (up to 99.4%) compared to toluene (up to 49.1%). The degradation efficiency by the CeT was greatest for the CeT-0.75 sample, followed by, in order, CeT-1.0, CeT-0.5, CeT-1.5, and CeT-2.0 samples in agreement with the order of the surface area and the particle size of the catalysts. According to the change of light source, the average decomposition efficiencies for toluene and o-xylene by CeT-0.75 were shown in the order of conventional daylight lamp > violet light emitting diodes (LEDs) > white LEDs. The decomposition efficiencies normalized to supplied electric power, however, were estimated to be in the following order of violet LEDs > white LEDs > conventional daylight lamp, indicating that the LEDs could be a much more energy efficient light source for the photodecomposition of target toluene and o-xylene using the CeT-0.75 photocatalyst.

Petroleum Hydrocarbon Removal from Wastewaters: A Review

“…However, TiO 2 is only responsive to the UV region due to its large band gap (3.2 eV). To expand the application of TiO 2 , the doping of metals were investigated to enhance the photo-response of TiO 2 toward the visible region [94]. Some indicative examples are given in following paragraphs.…”

“…There are many examples in the literature reporting the doping of TiO2 with various metals for BTEX degradation. Ce-doped TiO 2 nanostructures (CeT) with different amounts of Ce (0.5, 0.75, 1.0, 1.5, and 2.0 wt %) were synthesized using a sonochemical processing method by Lee et al [94]. The prepared CeT exhibited significantly improved photocatalytic performance towards the degradation of toluene and o-xylene, which was much higher than that observed for pure TiO2 and commercial P25 TiO2.…”

Volatile Organic Compounds (VOCs) Removal from Indoor Air by Heterostructures/Composites/Doped Photocatalysts: A Mini-Review

“…Direct transformation of VOCs in mineralization products seems to be an alternative to reduce indoor air contaminants [12,13]. Several advanced oxidation processes (AOPs) with good prospects for developing air cleaning technologies were considered: UV/ozonation [14][15][16], H 2 O 2 /ozonation [17][18][19] or photocatalysis [20][21][22]. The advantage of photocatalysis implementation in indoor air treatment is given by the absence of additional chemicals (such as H 2 O 2 ).…”

Preparation and Photocatalytic Properties of Metal-Doped ZnO Nanofilms Grown on Graphene-Coated Flexible Substrates

“…Semiconductor photocatalysis is a green environmental protection technology with the ability to remove organic pollutants in the air and water, and it is an effective way to solve the energy and environmental crisis [1]. At present, metal oxides such as TiO 2 [2], SnO 2 [3] and ZnO [4] have been used by researchers around the world to remove various pollutants by photocatalytic methods. Among them, ZnO exhibits excellent photocatalytic activity under ultraviolet (UV) light irradiation, and its high exciton binding energy (60 meV) provides it with efficient exciton emission at room temperature, making it an attractive wide band gap (3.37 eV) semiconductor photocatalyst [5,6].…”